Multiple sources have identified to French media one killer as Omar Ismaïl Mostefai, a 29-year-old of Algerian origin.

He was one of three gunmen to storm the Bataclan theatre.

Mostefai’s former home and birthplace in Courcouronnes, a town in Essonnes south of Paris, was searched on Saturday. Jean-Pierre Georges, a French MP, said the alleged terrorist also lived in Chartres, in south-west Paris, until 2012.

Mostefai had a criminal record, convicted of eight crimes between 2004 and 2010, but was never jailed. He was flagged as a radicalisation risk by French intelligence in 2010, Paris prosecutor Francois Molins said on Saturday.

In fact, a parking ticket casually discarded in the small rented vehicle was to tell them much more than they could have hoped – or, indeed, have feared. It had been issued in the Brussels district of Molenbeek.

Immediately the French security services will have been confident of two things: Islamic State was likely to have been behind the attacks, and the security services had dropped the ball.

A district of derelict warehouses, red-brick terraces and vibrant street life on the canals north-west of the centre of Brussels, Molenbeek was once known as Belgium’s “Little Manchester”. Today it was casually described by one Belgian broadcaster as a “den of terrorists”, where returnees from Syria have in recent years often made their home.

The district "enjoys a reputation for hardline clandestine Salafist cells," the Guardian reports, which Belgium security forces have yet to address:

Ayoub el-Khazzani, 25, a Moroccan national, who opened fire with a Kalashnikov on a high-speed Thalys train last August had lived there. The 29-year-old French national of Algerian origin, Mehdi Nemmouche, who killed three people at the Jewish Museum in Brussels in 2014 stayed in the district; as did one of those involved in the Madrid bombings in 2003.

AP reports that seven people have been detained in Belgium in connection with the attacks.

More information will follow in due course as initial reporting gets refined and confirmed. No doubt hardliners in the U.S. will be all over the bobblehead shows this morning rattling their talking points and vilifying immigrants, migrants, refugees, and Muslims wholesale. Someone will exhume Dick Cheney who will blame Obama and advocate bombing an unrelated country. It's Sunday. That's how it goes.